Blunted Heart Rate Dip During Sleep and All-Cause Mortality

Abstract

Background: Although it has been somewhat overlooked, resting heart rate is an established predictor of cardiovascular and noncardiovascular outcome. We assessed the determinants and mortality associations of heart rate measured during ambulatory blood pressure monitoring (ABPM) to evaluate its informativeness during activity and sleep. Methods: We studied a cohort of 3957 patients aged 55 ± 16 (mean ± SD) years (58% treated for hypertension) who were referred for ABPM during 1991 to 2005. Heart rate nondipping was defined as follows: (awake value−sleep value)/awake valueϽ0.1. Linear and logistic regression models assessed covariate associations with ambulatory heart rate indices. All-cause mortality was analyzed by Cox proportional hazards modeling. Results: Female sex, body mass index (calculated as weight in kilograms divided by height in meters squared), and treated diabetes were positively related to awake and sleep heart rate, whereas age and treated hypertension were inversely associated. All these variables were associated with lower sleep-related heart rate dipping magnitude. Multivariate-adjusted odds ratios (95% confidence intervals) for heart rate nondipping were 1.02 (1.02-1.03) per year of age; 1.05 (1.03-1.06) for body mass index; 1.39 (1.20-1.60) for women; 1.30 (1.12-1.51) for nappers; 2.19 (1.87-2.57) for treated hypertensive patients; and 1.38 (1.09-1.76) for treated diabetic patients. Mortality analysis according to deciles of the different heart rate variables showed a robust linear relationship only for heart rate dip and a hazard ratio of 2.67 (1.31-5.47) for the lowest vs the highest decile. Conclusions: In clinical practice, ambulatory heart rate adds prognostic information beyond that of other ABPM predictors. Heart rate measures during sleep, and in particular the absence of dipping of heart rate to sleep levels, were independently associated with all-cause mortality.

A modified ambulatory arterial stiffness index is independently associated with all-cause mortality

“…It has been recently referred to as 'a trove of hidden gems'. 32 Such 'gems' include identification of non-dipping 33,34 and nocturnal hypertension, 33,35 the morning surge, 33,36 exposing white-coat hypertension, 33,37 uncovering masked hypertension 33 and identifying the prognostic importance of ambulatory heart rate 38,39 AASI is the most recent candidate for this list. Its predictive ability has been inconsistent and its implications somewhat vague.…”

Cardiovascular Disease and Sleep

“…Several studies have revealed that a"non-dipping"BP pattern is associated with an increased risk for morbidity and mortality in patients with CVD 37)- 40) . Insomnia is prevalent (50%) in patients with HF, which is associated with autonomic dysregulation, activation of the renin-angiotensin-aldosterone system (RAAS), and lower exercise capacity, while the presence of insomnia is associated with poor clinical outcome in patients with HF 41) .…”

Referral of Women to Ambulatory Blood Pressure Monitoring

“…5 Such lack of heart rate dipping adds to the importance of nocturnal monitoring in women because it may be an independent risk marker. 5 It would be interesting to learn the IDACO findings in this matter.…”